Module 6 (gene manipulation)

Question 1

PCR full form

Answer 1

polymerase chain reaction

Question 2

Steps of PCR

Answer 2

1) double stranded DNA denatured by heating to 95C

2) at 60C primers (short sections of DNA) anneal to complementary bases

3) 72C taq polymerase extends the single stranded DNA, creating new double stranded DNA

4) Process repeated 25-35 times

Question 3

What are primers and why needed for PCR

Answer 3

Short sections of DNA
Needed because dna polymerase cannot bind to single stranded dna

Question 4

Taq polymerase

Answer 4

DNA polymerase isolated from thermus aquaticus (a thermophylic bacteria)

It is a thermostable enzyme

Question 5

Why thermostable taq polymerase useful in PCR

Answer 5

Does not denature at high temperatures
PCR can be cycled repeatedly without stopping to reload with enzyme so DNA can be be formed continuously

Question 6

Restriction enzyme other name and what they recognise in DNA

Answer 6

Endonuclease
Palindromic sequence

Question 7

Name of DNA end cut with restriction enzymes

Answer 7

sticky ends

Question 8

Gel electrophoresis steps

Answer 8

1) Cut DNA into fragments of different lengths using restriction enzymes

2) Agarose gel placed in buffer solution (helps conduct electricity), DNA samples pipetted into wells in the gel

3) Apply electric current
- gel connected to power supply
- DNA is negatively charged, so moves towards anode

4) Smaller fragments move faster so travel further

5) Fluorescent probe added to gel and viewed under UV to seen banding pattern

Question 9

DNA profiling/ genetic fingerprinting

Answer 9

Number of short tandem repeats compared by using gel electrophoresis to analyse lengths

Question 10

Creating a DNA profile steps

Answer 10

1) DNA obtained by moth swab and amplified using PCR

2) DNA digested by restriction enzymes which cut at recognition sites into fragments of length that will vary for the individual

3) Fragments separated by gel electrophoresis

4) banding pattern compared

Question 11

Genetic engineering

Answer 11

A process that uses lab based techniques to alter DNA makeup of an organism

Question 12

Recombinant DNA

Answer 12

DNA formed by by joining DNA from different sources

Question 13

Transgenic organism

Answer 13

Organism genetically engineered to include gene from different species

Question 14

How required gene is obtained for genetic engineering

Answer 14

DNA probe used to locate gene (complementary to the section of wanted gene)

Restriction enzymes used to cut it out

Question 15

Examples of vectors for genetic engineering

Answer 15

Plasmids
bacteriophages (virus that infects bacteria)

Question 16

How copy of gene placed in vector for genetic engineering

Answer 16

Same restriction enzyme that was used to cut gene of interest used to cut open vector
- sticky ends complementary

Marker gene inserted

DNA ligase joins sugar phosphate backbones of complementary sticky ends - ligation

Recombinant DNA produced

Question 17

Electroporation steps
(allows plasmids to enter bacteria)

Answer 17

• cells and plasmids mixed together
• electrical pulse applied, causing pores to form
• plasmids enter through pores and pores seal

Question 18

Marker genes old and new used in genetic engineering

Answer 18

Old
Antibiotic resistance marker gene
- antibiotic resistance could spread

New
fluorescent marker gene

Question 19

Alternative method for isolating a gene in genetic engineering (not restriction enzymes)

Answer 19

• isolate mRNA for the desired gene and make a single copy of the DNA using the enzyme reverse transcriptase
• another copy made by adding DNA polymerase so that a double stranded length of DNA is made

Question 20

Things in each test tube for chain termination method for sequencing DNA (sanger sequencing)

Answer 20

DNA polymerase
DNA to be sequenced
Free DNA nucleotides
Primers

Modified DNA nucleotides (different one in each)

Question 21

Process of gel chain termination method for sequencing DNA

Answer 21

• tubes undergo PCR
• Strands of different lengths since cut where the modified nucleotides added
• DNA fragments seperated by electrophoresis
• the bases from the end upwards are the complementary to the DNA sequence

Question 22

Maximum length for sanger sequencing so how to sequence entire genome

Answer 22

750 base pairs

Genome cut into smaller sections and each sequenced

Question 23

Steps in order to sequence the whole genome of the organism (library)

Answer 23

• genome cut into smaller pieces using restriction enzymes
• The fragments inserted into Bacterial Artificial Chromosomes
• BACs inserted into bacteria
• Bacterias divide into identical cells
• DNA library
• DNA extracted and cut using restriction enzymes
• Each DNA can be sequenced

Question 24

Synthetic biology

Answer 24

Designing new artificially made proteins

Question 25

Bioinformatics

Answer 25

Using software and computers to analyse, organise and store biological data

Question 26

Computational biology

Answer 26

using computers to study biology eg. create simulations and models

Question 27

Uses of genetically modified organisms

Answer 27

- insect resistant plants - producing drugs from animals - using pathogens for research

Question 28

Pros and cons of using GMO for insect resistant plants

Answer 28

Pros Farmers use less fertiliser Can be made to be more nutritious Cons Encourages monoculture which reduces biodiversity Could interbreed with wild

Question 29

Pros and cons of using GMO to produce drugs from animals (pharming) (eg. DNA fragments inserted into goat embryo)

Answer 29

Pros Drugs can be made in larger quantities Cons May cause harmful side effects to animal

Question 30

Pros and cons of using GMO for pathogens in research

Answer 30

Pros Diseases can be treated Cons Scientists could get infected, causing outbreak Could be used in biowarfare

Question 31

Positive and negative of biological patents

Answer 31

Makes money so encourages competition so products made quicker Farmers in poorer countries cannot afford genetically modified seeds

Question 32

Gene therapy

Answer 32

Altering alleles inside cells to cure genetic disorders

Question 33

Somatic gene therapy

Answer 33

Altering alleles in the body cells especially cells most affected - but they could still pass on the disease - difficult to get all cells to take up allele - requires repeated treatment - short term

Question 34

Germ line gene therapy

Answer 34

Altering alleles in the sex cells Offspring don't have disease Long term

Question 35

Disadvantages of gene therapy

Answer 35

- may be used for cosmetic - very expensive - body may identify vector as foreign - allele may be put in wrong cell, causing cancer

Question 36

Somatic cell nuclear transfer cloning steps

Answer 36

1) somatic cell taken from tissue cell donor. Diploid extracted 2) oocyte taken from second sheep and nucleus removed to become enucleated 3) Diploid nucleus inserted in oocyte 4) Fused together and electric current to stimulate to divide 5) Embryo planted in surrogate

Question 37

Embryo meaning

Answer 37

Cluster of totipotent diploid cells

Question 38

Artificial embryo twinning cloning procedure

Answer 38

1) Egg extracted from female and fertilised in petri dish 2) Left to divide forming in vitro embryo 3) Cells from embryo put into separate petri dishes 4) Embryos inserted in surrogates

Question 39

For and against of animal cloning

Answer 39

Desirable characteristics always passed on Infertile animals can be reproduced Can be cloned at any time Expensive and time consuming No genetic variability Clones may have shorter life

Question 40

Vegetative propogation

Answer 40

Natural production of plant clones from non reproductive tissues

Question 41

Natural plant cloning examples

Answer 41

Stolens (runners) Suckers (shoots underground) Tubers (sprouting potato eyes) Bulbs

Question 42

Plant clones from cuttings steps

Answer 42

- scalpel to cut root or shoot - remove leaves - dip in rooting powder (hormones) - Plant in pot - Warm moist environment by covering with plastic bag

Question 43

Plant clones by tissue culture and micropropagation

Answer 43

- cells from roots and shoots taken from original plant - cells sterilised so no competition for resources from microorganisms - Cells in growth medium under ascetic conditions - mass of cells subdivided quickly - when grown planted in soil

Question 44

Arguments for and against artificial plant cloning

Answer 44

- high yield - desirable characteristics - any time of year - more vulnerable to a disease - training, equipment expensive - disease, contamination

Question 45

What is biotechnology

Answer 45

Harnessing the process in living organisms to produce useful products such as foods and medicines

Question 46

Why microorganisms used in biotechnology

Answer 46

Simple growth requirements - little space and food cheap Reproduce quickly Can be grown on industrial scale

Question 47

Beer making process

Answer 47

Yeast fermentation glucose - pyruvate - ethanal (+CO2) - ethanol anaerobic respiration

Question 48

Baking process

Answer 48

Ethanol pathway of anaerobic respiration Fermentation of yeast CO2 causes to rise and ethanol evaporates

Question 49

Cheese making process

Answer 49

.

Question 50

Yogurt making

Answer 50

.

Question 51

Penicillin produciton

Answer 51

.

Question 52

Insulin produciton

Answer 52

.

Question 53

Bioremediation

Answer 53

.

Question 54

Mycoprotein

Answer 54

.

Question 55

Adv and dis of microorganisms in biotechnology

Question 56

Fermentation vessel features

Question 57

Continuous culture fermentation

Question 58

Batch culture fermentation

Question 59

Continuous culture fermentation adv and dis

Question 60

Batch culture fermentation adv and dis

Question 61

Primary metabolites and stationary metabolites in fermentation

Answer 61

.

Question 62

Lag phase Log phase Stationary phase Death phase